Binocular stereo-navigation for three-dimensional thoracoscopic lung resection

This study was approved by the institutional ethics committee of Tokyo Women’s Medical University (no. 2760). The patients who were 20 years old or older received both oral and written information regarding the procedure. All patients participating in this study were gave informed consent for them to allow the surgeons to use the binocular stereo-navigation system during 3-D TSLRs and the publication of their individual clinical details in publication. From July 2001, our department began to use a virtual 3-D pulmonary model on a personal computer (PC) (CF-AX2, Panasonic, Osaka, Japan) for preoperative simulation before thoracoscopic lung resection and for intraoperative navigation during operation. Furthermore, binocular stereo-navigation during 3-D TSLR has been started from January 2012. All patients were examined by high-resolution computed tomography (HRCT) without contrast agents. The creation of patient-actual virtual 3-D pulmonary model is previously described [12‐14]. After 120 of 1-mm thin-sliced HRCT-scan images of tumor and hilum in digital imaging and communications-in-medicine (DICOM) format were uploaded to the PC, homemade software, named “CTTRY” (Tokyo Women’s Medical University, Tokyo, Japan), allowed surgeons to mark pulmonary arteries, veins, bronchi, and tumor on the HRCT images manually and attempted to reconstruct an anatomical model with the help of anatomically correct images (Fig. 1a-c). The locations and thicknesses of the pulmonary vessels and bronchi were rendered various sizes of cylinders. In accordance with the resulting numerical data, a 3-D image was reconstructed by Metasequoia shareware (Metasequoia, http://​metaseq.​net/​) (Fig. 1d). Subsequently, the data of the reconstructed 3-D images by Metasequoia were converted to Autodesk data with Autodesk® 3ds Max® 2012 (Autodesk, San Rafael, CA, USA). Finally, REMO Exporter® (3D Incorporated, Kanagawa, Japan), which can reproduce real-time computer graphics (CG) from Autodesk data, was able to show 3-D CG on a stereoscopic vision display. Reconstructed 3-D pulmonary images appeared as left and right-eye view images on the screen of PC and overlaid 3-D images on a monitor. Surgeons were able to watch the 3-D CG of the reconstructed 3-D pulmonary model on a 3-D liquid crystal (LC) monitor (Panasonic Healthcare, Tokyo) by REMO Viewer® (3D Incorporated) (Fig. 1e). Wearing 3-D polarized glasses, surgeons were able to manipulate the reconstructed 3-D images on a 3-D LC monitor for simulating virtual surgical procedures such as reshaping, cutting, and moving preoperatively. Three-dimensional TSLR was performed by a 3-D digital vision system (Shinko Optical, Tokyo, Japan). Surgeons wearing 3-D polarized glasses performed 3-D TSLR, watching the reconstructed 3-D images on a 3-D LC monitor intraoperatively (Fig. 2). The surgical procedure was performed under general anesthesia with single-lung ventilation, and the patient was allowed to be in the lateral decubitus position. Depending on segments or subsegments that would be removed surgically, an operating surgeon stood to face patient’s anterior chest or back. A 2.5-to-5-cm access incision was placed in the anterior axillary line in the 4th or 5th intercostal space (ICS). An assist port was placed at the midaxillary line of the 7th or 8th ICS, and a camera port was placed along the same ICS in the posterior axillary line. A rigid 30° endoscope was used. The segments were divided by the combined used of an electrocautery, ultrasonically activated device, and a stapler. All patients with primary lung cancer were preoperatively staged as N0 by HRCT of the chest and positron emission tomography.